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<table width="100%" summary="page for Airq"><tr><td>Airq</td><td style="text-align: right;">R Documentation</td></tr></table>

<h2>Air Quality for Californian Metropolitan Areas </h2>

<h3>Description</h3>

<p>a cross-section from 1972
</p>
<p><em>number of observations</em> :  30
</p>
<p><em>observation</em> :  regional
</p>
<p><em>country</em> :  United States
</p>


<h3>Usage</h3>

<pre>data(Airq)</pre>


<h3>Format</h3>

<p>A dataframe containing :
</p>

<dl>
<dt>airq</dt><dd><p>indicator of air quality (the lower the better)</p>
</dd>
<dt>vala</dt><dd><p>value added of companies (in thousands of dollars)</p>
</dd>
<dt>rain</dt><dd><p>amount of rain (in inches)</p>
</dd>
<dt>coas</dt><dd><p>is it a coastal area ? </p>
</dd>
<dt>dens</dt><dd><p>population density (per square mile)</p>
</dd>
<dt>medi</dt><dd><p>average income per head (in US dollars)</p>
</dd>
</dl>



<h3>References</h3>

<p>Verbeek, Marno (2004) <em>A Guide to Modern Econometrics</em>, John Wiley and Sons, chapter 4.
</p>


<h3>See Also</h3>

<p><code>Index.Source</code>, <code>Index.Economics</code>, <code>Index.Econometrics</code>, <code>Index.Observations</code></p>


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